Species ca. 50 (15 in the flora): se and sc United States, West Indies, Central America, and South America.

The species of Hymenocallis are some of the most difficult to identify from herbarium specimens. Distinguishing field characteristics such as position, surface, texture, and color of the leaves, and three-dimensional shape and margin of the staminal corona, are undeterminable on most herbarium specimens. These characteristics, as observed in the field, are discussed in the treatment of each species, and distinguishing features are emphasized for their usefulness in identification. With the exception of dimensions for fruits, seeds, and some bulbs, all measurements presented are from pressed, dried specimens. Variations in habitat and distribution are also emphasized, and they are often used in the key to support character distinctions.

The first eight Hymenocallis species treated here were classified by H. P. Traub (1962) in the Caroliniana Alliance. Species in this group primarily have 1–3 ovules per locule and deciduous, sessile, liguliform or oblanceolate leaves. They are distributed in northern Florida and throughout wetland areas of the southeastern United States. Species studied to date have a base chromosome number of x = 20.

Hymenocallis rotata, H. godfreyi, H. puntagordensis, H. palmeri, and H. henryae (species 9–14) were all classified in Traub’s Henryae Alliance. They have distinctly larger ovaries than the species classified in Traub’s Caroliniana Alliance, having 4–8 ovules per locule, as well as coriaceous, suberect to erect, liguliform leaves. All species in the Henryae Alliance treated here occur in Florida. There is considerable chromosome diversity among these taxa, but the base number of many is x = 23.

Hymenocallis latifolia is the only spider-lily in the flora that is classified in Traub’s Caribaea Alliance. Species in this alliance are characterized by sessile, liguliform, evergreen leaves. Many have 2–3 ovules per locule and a base number of x = 23.

D. S. Correll and M. C. Johnston (1970) and D. S. Correll and H. B. Correll (1972) recognized three species of spider-lilies in Texas, and L. H. Shinners (1951) recognized two. We recommend a thorough investigation of Hymenocallis in Texas and adjacent states to achieve a clearer understanding of the southwestern spider-lily species.

Like many other amaryllids, Hymenocallis species contain various alkaloids. It is not recommended that plant parts be eaten or even touched by allergic individuals (J. A. Bauml 1979).

The precise localities of the bulb collections of Hymenocallis collected by Mary G. Henry from which Traub described numerous new species of Hymenocallis were determined from the field diaries of Mary G. Henry, courtesy of Josephine de N. Henry, President Emerita of the Henry Foundation for Botanical Research. This treatment would not have been possible without this critical information.

SELECTED REFERENCES

Flory, W. S. 1976. Distribution, chromosome numbers and types of various species and taxa of Hymenocallis. Nucleus (Calcutta) 19: 204–227. Flory, W. S. 1978. Known distributions of Hymenocallis Salisbury in North and Middle America and the West Indies. Pl. Life 34: 47–59. Morton, C. V. 1935. A check list of the bulbous Amaryllidaceae native to the United States. Year Book Amer. Amaryllis Soc. 2: 80–83. Sealy, J. R. 1954. Review of the genus Hymenocallis. Kew Bull. 1954: 201–240. Shinners, L. H. 1951. The north Texas species of Hymenocallis (Amaryllidaceae). Field & Lab. 19: 102–104. Traub, H. P. 1962. Key to the subgenera, alliances and species of Hymenocallis. Pl. Life 18: 55–72.